The invention is based on a method for detecting fires.
Fire detectors react to changes in the environment. Among such changes caused by fire are smoke that occurs, a temperature increase, and gases produced in a fire. For detecting these parameters, scattered light sensors are used for smoke detection, temperature sensors are used for detecting the temperature increase, and gas sensors are used for gas detection. With gas sensors, both chemical and physical gas sensors are possible. In a fire detector, sensor signals derived from such sensors are picked up cyclically, specifically by an evaluation circuit. A fire is indicated whenever a predetermined alarm threshold is exceeded by the sensor signal. However, the problem of so-called interference variables that can cause false alarms also exists. These include cigarette smoke, disco fog, dust, and electromagnetic interference.